The present invention relates to an electrical switch and, more particularly but not exclusively, to a rotary switch.
Electrical switches are normally connected by electric cables to other parts of an electrical circuit. For those switches having external terminals, the cables are often connected thereto by soldering. Cable connection of the self-gripping type is known, in which an internal fixed contact is configured to have a resilient end behind a hole. Upon insertion of an electric cable into the hole, the contact end is deflected inwards to thereby grip the cable end against a surface on the opposite side. As the grip of the contact end upon the cable end is often small in area, the resulting contact may not be satisfactory in terms of contact resistance.
The invention seeks to mitigate or at least alleviate such a problem by providing an improved electrical switch.
According to the invention, there is provided an electrical switch comprising a casing, an operator supported by the casing for movement, and a plurality of fixed contacts and a moving contact in the casing. The moving contact is movable by the operator to come into contact with and out of contact from the fixed contacts. The casing has a hole for insertion of an electric cable. At least one of the fixed contacts has a resilient end positioned behind the hole and deflectable inwards by an end of the cable upon insertion, a part integral with the contact end, and a separate conductor in electrical contact with the contact part and positioned adjacent the contact end. The contact end is operable to press the cable end, while being deflected thereby, against the conductor, together providing a double-sided electrical contact to the cable end.
Preferably, said at least one fixed contact, including the conductor, has a generally triangular structure.
More preferably, said at least one fixed contact has one section providing the contact end and another section providing the contact part, the two sections together with the conductor representing respective sides of the structure.
In a preferred embodiment, said at least one fixed contact comprises a generally Z-shaped body having a front section for contact by the moving contact, a rear section providing the contact end, and a middle section extending therebetween.
More preferably, the fixed contact body includes a bend between the front and middle sections, the bend providing the contact part.
It is preferred that the casing includes a side wall having an inner surface, lying against which the conductor is fixed.
It is further preferred that the conductor has one end engaged by a recess adjacent the inner surface and an opposite end pressed by the contact part against the inner surface.
In a specific construction, the operator is supported within the casing for rotation, the fixed contacts are disposed around the operator, and the moving contact is mounted on the operator for rotation therewith.
More specifically, the electrical switch is a rotary switch with the operator being rotatable over 360xc2x0 in opposite directions.